1. Field of the Invention
The present invention relates to a ternary (tristable) logic circuit having resonant-tunneling transistors, such as resonant-tunneling hot electron transistors (RHETs) and resonant-tunneling bipolar transistors (RBTs). More particularly, it relates to a tristable gate circuit, a latch circuit having tristates, and a memory cell having tristates.
2. Description of the Related Art
Binary logic circuits have been extensively used and the fact that logic circuits of e (a base of a natural logarithm, e=2.718), are ideal has been proved in theory. Theoretically, the performance of a ternary logic circuit is superior to that of a binary logic circuit, and therefore, attempts have been made to realize ternary logic circuits. The prior art ternary logic circuits are not used in practice, because of small margin, complex circuit arrangement, etc.
Conversely, the principle of a resonant-tunneling transistor, such as a RHET has long been known. Recently, due to advances in semiconductor processing technology, such as molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MOCVD), practical RHETs have been developed (e.g., "RESONANT-TUNNELING HOT ELECTRON TRANSISTORS (RHET): POTENTIAL AND APPLICATIONS", N. Yokoyama, et al, Japanese Journal of Applied Physics, Vol. 24, No. 11, November, 1985, pp. L853-L854).